Hey Max, i've never run into this issue myself, but did a little reading and this is what I found:

A dynamic page is one generated by a database driven application, such as blog or forum software. A file name is appended by a query string, looking something like this:

http://www.example.com/page.php?id=13

Where a query string is used, the 301 redirect solution for static pages above will not work; you'll need to use a rewrite solution. Using the page.php?id=13 example, here's what you'll need to use in your htaccess file: